I got the sense that Windows 7 was like a reversion of sorts due to complaints about Vista. Vista was supposed to be this whole new generation of OS, and a lot of features I used to hear about were scaled back by the time it came out (more graphical stuff using transparency, etc). So it looks like they kept biting off more than they could chew, to the point now of having to revert to the old number series. (Not sure how the graphics and other features compare to Vista or the older versions).
But who knows. Maybe it was a beta test, and they just made it look like the new system was an afterthought. Never know what these geniuses will do to make the profit charts go up.
I was one of thsoe trying to hook a Vista laptop up to a home network of XP computers. The laptop had the internet connection through the router, but could not "see" the XP's. the Xp's could access the Vista, however. A lot of people had this problem, and the information was hard to find. It seemed to show that Vista was poorly thought out to the extent of being so incompatible with XP. I think 7 is supposed to fix this.
What solved my problem: one of the suggestions mentioned the LPT1 (?) drivers for the XP (apart of XP sp3), but I found that it already had this. What's needed is the hotfix, mentioned on the same Microsoft help page. Now, the XP appeared on the vista network map, though it still could not be clicked. Right at that time, the Service Pack 1 for Vista came out. (so there is a service pack being offered as an alternative to the new OS). That got rid of that stupid "Microsoft Publication Service Device Host" that appeared under "Network" where the network map should have first appeared. I also needed to download Vista drivers to the printer to be able to access it from the laptop. Then, all of a sudden, I had full two way access.